I wouldn't make any such assumptions since most likely they will turn futile, while those than won't will be correct just like a broken clock is right twice a day
He may "favor" the dollar in different ways and poses
And what he is talking about right now looks more like a sadistic approach, and somehow you shouldn't be surprised. So this favoring may cause the dollar to be consistently losing its value if it gets ridden to death, metaphorically speaking. In this manner, even if Trump doesn't favor Bitcoin or even if he doesn't know about it altogether, he may in fact inadvertently make it a good service